Answer this question truthfully
### Question: What causes Psoriatic arthritis?
### Response: Psoriasis is a common, chronic skin condition that causes red patches on the body. About 1 in 20 people with psoriasis will develop arthritis with the skin condition. In most cases, psoriasis comes before the arthritis.
The cause of psoriatic arthritis is not known, but genes, body defence mechanisms and environmental factors may play a role.